小麦秸秆生物质炭施用对不同耕作措施土壤碳含量变化的影响

Effects of Wheat Straw-derived Biochar Application on Soil Carbon Content Under Different Tillage Practices

为探究生物质炭施用对不同耕作条件下土壤碳含量的影响,通过室内恒温培养试验,以免耕和翻耕土壤为研究对象,分别添加0、5和20 g·kg^(-1)的小麦生物质炭,分析生物质炭对免耕和翻耕土壤有机碳(SOC)、可溶性有机碳(DOC)、微生物生物量碳(MBC)、易氧化有机碳(ROC)、pH、无机碳(SIC)、水溶性Ca和Mg以及土壤CO_(2)排放的影响.结果表明:(1)与对照相比,不同用量的生物质炭添加下,免耕处理土壤SOC、ROC、DOC、水溶性Ca和Mg分别增加20.3%~105.6%、0.5%~36.0%、0.8%~30.5%、3.5%~42.3%和2.4%~75.2%;翻耕处理土壤SOC、ROC、DOC、水溶性Ca和Mg分别增加29.2%~145.1%、1.3%~63.9%、2.4%~55.6%、18.2%~89.8%和10.1%~150.5%;且随着生物质炭施用量增加而增大.5 g·kg^(-1)的小麦生物质炭施用量下,免耕土壤CO_(2)累积排放量最大,而翻耕土壤CO_(2)累积排放量随着生物质炭施用量增加而增大.培养结束时,与对照相比,翻耕土壤MBC增加35.5%~45.7%,且土壤MBC随着生物质炭施用量的增加而增大.生物质炭施用对翻耕和免耕土壤p H和SIC没有显著性影响.(2)相同用量的生物质炭施用条件下,与翻耕相比,免耕土壤CO_(2)累积排放量、SOC、ROC、DOC、MBC、水溶性Ca和Mg含量分别增加了34.2%~79.0%、8.9%~45.5%、28.2%~73.9%、40.4%~78.4%、0.2%~131.7%、8.7%~39.8%和0.3%~61.0%;土壤p H和SIC分别降低0.08~0.17个单位和2.4%~13.9%.综上所述,生物质炭添加增加了免耕和翻耕土壤总有机碳、活性有机碳、水溶性Ca和Mg的含量以及土壤CO_(2)累积排放量,但对土壤无机碳含量没有显著性的影响.

This study intended to examine the influence of biochar application on soil carbon content under different tillage conditions.For this,an indoor incubation experiment was performed with treatments included wheat straw-derived biochar application(0,5,and 20 g·kg^(-1))and soil with different tillage measures(ploughing and no-tillage).The effects of biochar addition on soil organic carbon(SOC),dissolved organic carbon(DOC),soil microbial biomass carbon(MBC),readily oxidized organic carbon(ROC),soil inorganic carbon(SIC),p H,water soluble calcium and magnesium,and soil CO_(2)emissions were analyzed.The results showed that:(1)Compared with the control,the contents of SOC,ROC,DOC,and water soluble Ca and Mg increased by 20.3%-105.6%,0.5%-36.0%,0.8%-30.5%,3.5%-42.3%,and 2.4%-75.2%in the no-tillage treatments,respectively;and the contents of SOC,ROC,DOC,water-soluble Ca and Mg increased by 29.2%-145.1%,1.3%-63.9%,2.4%-55.6%,18.2%-89.8%,and 10.1%-150.5%in the ploughing treatment,respectively,under different dosage biochar amendments,and was enhanced with an increase in the biochar application amount.Cumulative CO_(2)emissions were highest with biochar amendment at 5 g·kg^(-1)under the no-tillage soil condition;however,this increased with an increase in the biochar amount in the ploughing treatment.At the end of incubation experiment,the soil MBC content increased by 35.5%-45.7%compared with the control treatment;however,there was no significant effect on soil p H and SIC between the treatments.(2)Compared with the ploughing treatment,the cumulative CO_(2)emissions,SOC,ROC,DOC,MBC,and water-soluble Ca and Mg contents of the no tillage treatment increased by 34.2%-79.0%,8.9%-45.5%,28.2%-73.9%,40.4%-78.4%,0.2%-131.7%,8.7%-39.8%,and 0.3%-61.0%,respectively,while soil p H and SIC decreased by 0.08-0.17unit and 2.4%-13.9%,respectively,under the same biochar amendment treatments.Overall,the addition of biochar significantly increased soil organic carbon,active organic carbon,soil water soluble calcium and magnesium content,and soil cumulative CO_(2)emissions,but no significant effect was observed on soil inorganic carbon content.